Comparison of fast MRI-based individual thrombolysis therapy for patients with superacute infarction

MRI-guided thrombolysis for lenticulostriate artery stroke within 12 h of symptom onset

Stroke thrombolysis treatment is generally administered within 4.5 h, but a greater time window may be permitted depending upon the ischemic penumbra on neuroimaging. This observational cohort study investigated the outcomes of thrombolysis given within 12 h after symptom onset of lenticulostriate artery stroke. The population comprised 160 patients. Thrombolysis was administered via tissue plasminogen activator, alteplase (TPA). Thrombolysis was indicated by a mismatch between diffusion-weighted imaging (DWI) and T2-weighted imaging (T2WI), that is, an acute ischemic lesion on DWI without a corresponding lesion on T2WI. Demographics and medical history were compared with the modified Rankin scale (mRS) score, to reflect outcome. Patients with a favorable clinical outcome (mRS 0–1) had significantly lower hypertension, baseline NIH Stroke Scale (NIHSS) score, and admission systolic/diastolic blood pressure compared with patients with mRS 2–6. Lower admission systolic blood pressure and NIHSS score were significantly associated with favorable outcome. In patients either with IV-TPA within 4.5 h, or between 4.5 and 12 h, lower admission systolic blood pressure and/or NIHSS score similarly independently predict favorable outcome. However, in all groups, the onset-to-treatment time did not significantly influence the outcomes. We conclude that in our cohort higher admission systolic blood pressure and higher baseline NIHSS and not time were associated with poor outcome in patients with magnetic resonance-guided thrombolysis within 12 h of isolated lenticulostriate artery stroke, therefore loosening the traditionally perceived dependency of outcome on time.

Treating ischaemic stroke with intravenous tPA beyond 4.5 hours under the guidance of a MRI DWI/T2WI mismatch was safe and effective

Purpose

Clinical trials have provided evidence that treating patients with acute ischaemic stroke (AIS) beyond 4.5 hours was feasible. Among them using MRI diffusion-weighted imaging/fluid attenuation inversion response (DWI/FLAIR) mismatch to guide intravenous tissue plasminogen activator (tPA) was successful. Our study explored the outcome and safety of using DWI/T2-weighted imaging (T2WI) mismatch to guide intravenous tPA therapy for patients with AIS between 4.5 hours and 12 hours of onset.

Method

This was a retrospective study. Records of 1462 AIS patients with the time of onset of <12 hours were reviewed. Those had MRI rapid sequence study and had hyperintense signal on DWI but normal T2WI and received intravenous tPA up to 12 hours of onset were included in the analysis. Their demographics, risk factors, post-tPA complications, National Institutes of Health Stroke Scale (NIHSS) scores and outcome were recorded and analyse. χ² was used to compare the intergroup variables. SAS was used to perform statistical calculation. A p<0.05 was considered statistically significant.

Results

Of 1462 identified, 601 (41%) patients were entered into the final analysis. Among them, 327 (54%) had intravenous tPA within 4.5 hours of onset and 274 (46%) were treated between 4.5–12 hours. After intravenous tPA, 426 cases (71%) had >4 pints of improvement on NIHSS score within 24 hours. Postintravenous tPA, 32 (5.32%) cases had haemorrhagic transformation. 26 (4.33%) were asymptomatic ICH and 4 (0.67%) died. At 90 days, 523 (87%) achieved a modified Rankin scale of 0–2.

Conclusion

Using MRI DWI/T2WI mismatch to identify patients with AIS for intravenous tPA between 4.5 hours and 12 hours was safe and effective. The outcome was similar to those used DWI/PWI or DWI/FLAIR mismatch as the screening tool. However, obtaining DWI/T2WI was faster and avoided the need of contrast material.